Bike tire pressure calculator
Starting front and rear pressure for road, gravel, and mountain bikes.
Example: 75 kg rider, 8 kg road bike, 28 mm tubeless — front 66.4 PSI (4.6 bar), rear 70.6 PSI (4.9 bar).
How this bicycle PSI calculator works
Pressure scales with load over tire volume. Road uses a milder load/width curve (SRAM-like) so skinny tires do not shoot to 110 PSI and 32 mm does not go too soft. Gravel still uses the classic 15% drop fit. Labelled width plus inner rim estimates inflated size. Hookless rims cap at 73 PSI. Rougher terrain, tubes, and wet weather change the number. Front sits a little below rear. Starting point, not a lab spec.
Road bike tire pressure chart (75 kg rider)
Typical road setups on smooth dry tarmac, tubeless, hookless rim (73 PSI / 5 bar cap). A 28 mm tire is the default on most new road bikes. Go wider if you want more comfort at lower PSI — or if the calculator hits the hookless cap.
75 kg rider, 8 kg bike, tubeless, dry, hookless rim. Front / rear.
| Tire | Front | Rear |
|---|
| 25 mm | 68.6 PSI
4.7 bar | 73 PSI
5 bar |
| 28 mm | 66.4 PSI
4.6 bar | 70.6 PSI
4.9 bar |
| 30 mm | 65.3 PSI
4.5 bar | 69.5 PSI
4.8 bar |
| 32 mm | 63.6 PSI
4.4 bar | 67.7 PSI
4.7 bar |
What PSI for 28 mm road tires?
For a 75 kg rider on an 8 kg road bike with 28 mm tubeless tires on a 21 mm internal rim, this calculator gives 66.4 PSI front and 70.6 PSI rear (4.6 / 4.9 bar) on smooth dry tarmac. Add a few PSI for a heavier rider or inner tubes. Drop a few for worn roads, cobbles, or rain.
Gravel tire pressure chart (75 kg rider)
Hardpack gravel, tubeless. 40 mm is the usual starting width. Run less on rough or mixed gravel. Inner tubes need a little more than tubeless to avoid pinch flats.
75 kg rider, 10 kg bike, tubeless, dry. Front / rear.
| Tire | Front | Rear |
|---|
| 40 mm | 36.9 PSI
2.5 bar | 39.7 PSI
2.7 bar |
| 45 mm | 33.7 PSI
2.3 bar | 36.2 PSI
2.5 bar |
| 50 mm | 32.5 PSI
2.2 bar | 34.9 PSI
2.4 bar |
What PSI for 40 mm gravel tires?
For a 75 kg rider on a 10 kg gravel bike with 40 mm tubeless tires, this calculator gives 36.9 PSI front and 39.7 PSI rear (2.5 / 2.7 bar) on hardpack. Choose Rough in the calculator for chunkier surfaces.
Mountain bike tire pressure chart (75 kg rider)
Trail, tubeless, 29" assumed. MTB PSI is much lower than road — grip matters more than rolling resistance. 1.0 bar is usually plus tires or inserts, not a 2.4" trail tire.
75 kg rider, 13 kg bike, tubeless, dry. Front / rear.
| Tire | Front | Rear |
|---|
| 2.1" (54 mm) | 24 PSI
1.7 bar | 25.8 PSI
1.8 bar |
| 2.25" (57 mm) | 21.7 PSI
1.5 bar | 23.3 PSI
1.6 bar |
| 2.4" (61 mm) | 19 PSI
1.3 bar | 20.4 PSI
1.4 bar |
What PSI for 2.4" mountain bike tires?
For a 75 kg rider on a 13 kg trail bike with 61 mm (2.4") tubeless tires, this calculator gives 19 PSI front and 20.4 PSI rear (1.3 / 1.4 bar) on trail. Rocky terrain drops it a little. Tubes add a pinch-flat buffer.
Pressure is a guess. Wear is not.
You can nail PSI today and still replace a tire too late or too early if you are guessing kilometres. Tiiks adds every Strava ride to the tires (and the rest of the bike) automatically, then reminds you when service or replacement is due.
FAQ
What PSI should my bike tires be?
It depends on rider plus bike weight, tire width, bike type, and terrain — not the number on the sidewall. The sidewall is a maximum. Use the calculator above for a starting front and rear pressure, then drop a few PSI if the ride feels harsh or add a few if you are rolling the tire off the rim.
What PSI should 28mm road bike tires be?
For a typical 75 kg rider on 28 mm tubeless, this page calculates about 66.4 PSI front and 70.6 PSI rear on smooth tarmac. Heavier riders and inner tubes sit higher. 25 mm sits higher still; 32 mm sits lower.
How do I use a gravel tire pressure calculator?
Choose Gravel, pick hardpack or rough, then enter weight and tire width in millimetres (a 40 mm tire is 40, not 40 PSI). A 75 kg rider on 40 mm tubeless hardpack lands around 36.9 / 39.7 PSI front / rear. Run the rear a little higher than the front.
What PSI should mountain bike tires be?
Most trail tubeless setups sit in the low-to-mid 20s PSI, not road numbers. A 75 kg rider on 2.4" tires is about 19 PSI front and 20.4 PSI rear on trail in this calculator. XC a little higher, rocky or enduro a little lower. Tubes: add a few PSI.
Why is rear tire pressure higher than front?
The rear wheel carries a bit more of you (about 52% on a road bike, 53% on gravel). Front pressure is set a few PSI lower than rear so the front can still take braking load without going harsh. That is usually a 3–5 PSI gap, not 15.
Does a wider tire need lower PSI?
Yes. Volume goes up with measured width — including extra millimetres you gain on a wider internal rim — so the same rider can run lower pressure without bottoming the rim. That is why 28 mm road tires sit below a 25 mm pair, and why gravel tires are much lower still.
Should I use PSI or bar?
Same pressure, different unit. This calculator toggles both. Road riders often think in PSI; many European pumps and rim limits are in bar. 5 bar is about 72 PSI — a common hookless road rim maximum.
Do tubeless tires run lower pressure than tubes?
Usually yes. Tubeless can sit a little lower without pinching a tube. This calculator adds a few PSI for an inner tube (not a big percentage bump at already-high road pressures). Tubular is treated like tubeless for the starting number.
What about hookless rims and a 5 bar max?
Many hookless road rims (including a lot of Zipp-style carbon) cap at 5 bar / 73 PSI even if the tire sidewall is higher. This calculator defaults to hookless and will not recommend more than that. Never exceed the lower of tire or rim limit. If you need more support, fit a wider tire — or switch the bead control to hooked if that is what you actually have.
How does this compare to a SILCA or SRAM tire pressure calculator?
Same family of inputs: rider plus bike weight, labelled tire width, and inner rim. SILCA and SRAM/Zipp publish load-and-width tables; Vittoria-style calculators also run the front a few PSI below the rear. Road numbers here track SRAM more closely than SILCA’s higher “fastest breakpoint.” Terrain, tubes, wet weather, and a 73 PSI hookless cap still change the result. Use any of them as a starting point, then ride and tweak.
How does Tiiks help after I set pressure?
PSI is a pre-ride setup. Tiiks tracks how many kilometres those tires (and chain, cassette, pads) have actually done via Strava, so you service and replace on data instead of a guess.
Pressure is set. There's an app for the rest of the bike. Tiiks adds every Strava ride to those tires — and the chain, cassette, and pads — then reminds you before they fail. Free to try.
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